This invention relates to a scavenge port delivery for a two stroke engine and more particularly to an improved scavenge port configuration for an engine having an cylinder liner.
With two cycle internal combustion engines in particularly those of the crankcase compression type, there are provided one or more scavenge passages that extend through the cylinder block and open into the cylinder bore through a respective scavenge port. Frequently such engines employ liners that are pressed or cast into the cylinder block and the port configuration itself is formed by the liner. Conventionally, the side edges of the scavenge port opening are generally straight. That is, they are parallel to each other and thus somewhat confine the flow of the charge which issues from them. In addition, the use of such straight edges can give rise to turbulence at the periphery and reduce air flow.
It is, therefore, a principle object of this invention to provide an improved scavenge port configuration for an internal combustion engine.
It is a further object of this invention to provide a scavenge port arrangement for an internal combustion engine wherein the scavenge port side edges have flare to them so as to promote smooth entry of the charge into the cylinder bore.